Reference File Formats

File Formats

This page summarizes the file types FindRomCover reads, writes, and manages.

ROM files

Any file whose extension appears in the supported extensions list is treated as a ROM. The list is fully configurable and covers most cartridge, disk, tape, and archive formats used by retro platforms.

Default extensions include (short excerpt):

nes, sfc, smc, n64, z64, gb, gbc, gba, nds, 3ds, nsp, xci,
sms, md, gen, 32x, gg, gdi, cue, iso, bin, pbp, cso, chd,
zip, 7z, rar, gz, d64, t64, a78, wad, wbfs, ...

The full list is maintained in the application and can be edited under Settings > Edit Supported Extensions....

Cover images

Recognized input formats

Family	Extensions
Web and common	.png, .jpg, .jpeg, .bmp, .gif, .webp
High efficiency	.avif, .heic, .heif, .jxl, .jp2
TIFF	.tiff, .tif

All of these are recognized when checking whether a ROM already has a cover. Non-PNG images are converted to PNG when they are saved through FindRomCover or picked up by the watcher.

Output format

Property	Value
Format	PNG
Name	<rom base name>.png
Location	Image folder

Examples:

ROM	Cover
Sonic the Hedgehog (USA).zip	Sonic the Hedgehog (USA).png
Super Mario World.sfc	Super Mario World.png

Application files

File	Format	Purpose
Settings.dat	SQLite	All settings, secrets encrypted
QueryHistory.dat	SQLite	AI query history
ai-cache.json	JSON	AI verdict cache
ai-models.json	JSON	Cached model lists
mame.dat	MAME database	Arcade game descriptions
app.log, error.log, error_user.log	Text	Diagnostics
settings.dat.legacy	Encrypted legacy	Backup of the old settings file
settings.dat.corrupt	Quarantined	Unreadable settings database

See Data Storage for details.

Media used by the application

Asset	Format	Purpose
click.mp3	MP3	UI sound effect
Icons and images	PNG/ICO	Application UI

Related pages

• Supported Extensions
• Image Handling
• Data Storage